﻿    <p>
      The <em>IfcDirection</em> provides a direction in two or
      three dimensional space depending on the number of
      <em>DirectionRatio</em>'s provided. The <em>IfcDirection</em>
      does not imply a vector length, and the direction ratios does
      not have to be normalized.
    </p>
    <blockquote class="extDef">
      NOTE&nbsp; Definition according to ISO/CD 10303-42:1992<br>
      This entity defines a general direction vector in two or
      three dimensional space. The actual magnitudes of the
      components have no effect upon the direction being defined,
      only the ratios X:Y:Z or X:Y are significant.
    </blockquote>
    <blockquote class="note">
      NOTE&nbsp; The components of this entity are not normalized.
      If a unit vector is required it should be normalized before
      use.
    </blockquote>
    <blockquote class="note">
      NOTE&nbsp; Entity adapted from
      <strong>direction</strong> defined in ISO 10303-42.
    </blockquote>
    <blockquote class="history">
      HISTORY&nbsp; New entity in IFC1.0
    </blockquote>